Definition: An immunocytokine of the human monoclonal antibody fragment F16 (scFv) against the extra-domain A1 of tenascin-C fused, via a short 5-amino acid linker, to a recombinant form of the human cytokine interleukin-2 (IL-2) with potential immunostimulating and antineoplastic activities. The monoclonal antibody portion of the F16-IL2 fusion protein binds to tumor cells expressing the tumor associated antigen (TAA) tenascin-C. In turn, the IL-2 moiety of the fusion protein stimulates natural killer (NK) cells, macrophages and neutrophils and induces T-cell antitumor cellular immune responses thereby selectively killing tenascin-C-expressing tumor cells. In addition, F16-IL2 may potentiate the cytotoxicity of other chemotherapeutic agents. Tenascin-C, a glycoprotein of the extracellular matrix, is expressed in many cancer cell types.